incubator-cassandra-user mailing list archives

On Mon, Dec 13, 2010 at 6:43 PM, Daniel Doubleday
<daniel.doubleday@gmx.net>wrote:
> Oh - well but I see that the coordinator is actually using its own score
> for ordering. I was only concerned that dropped messages are ignored when
> calculating latencies but that seems to be the case for local or remote
> responses. And even than I guess you can assume that enough slow messages
> arrive to destroy the score.
>
That's odd, since it should only be tracking READ_RESPONSE messages... I'm
not sure how a node would send one to itself.
Maybe I misunderstand but that would not really lead to less load right. I
> don't think that inconsistency / read repairs are the problem which leads to
> high io load but the digest requests. Turning off read repair would also
> lead to inconsistent reads which invalidates the whole point of quorum reads
> (at least in 0.6. I think rr probability has no effect in strong reads in
> 0.7) . Again assuming I am not misinterpreting the code.
>
Ah, I see what you want to do: take a chance that you pick the two replicas
(at RF=3, at least) that should agree, and only send the last checksum
request if you lose (at the price of latency.)
-Brandon